Deficiency is rare in the UK, although the number of cases is increasing in some communities. It is more common in people who have little vitamin D in their diet and whose skins are rarely exposed to sunlight-for example, elderly people and some Asian women. Large doses can lead to high blood levels of calcium, especially in children, and may result in bone malformations, although this is extremely rare. There are no dietaly recommendations for adults who have a normal lifestyle involving exposure to sunlight.